This invention relates to a field effect transistor (FET) provided with a superlattice channel.
Insulated gate field effect transistors (IGFET) are semiconductor devices which are suitable for highspeed switching operation. Such a transistor comprises a source region, a gate region, a drain region, each region being formed within a single-crystalline silicon semiconductor, and an electrode arrangement therefor. The source and drain regions are fabricated by ion doping by which the threshold voltage can be controlled.
In such a conventional structure, carrier flow in on-state is limited to a very thin region contiguous to the gate insulated film, so that the mobilities of the electron and the hole are only about 300cm.sup.2 V/sec and 150cm.sup.2 V/sec due to interfacial scattering. furthermore, in the way of seeking high density of integrated circuits, a short channel length is desired and therefore the concentration of carriers must be made high. Because of this, the mobilities again become low.